Strange Tonearm Tweak. Long

Hi Basement - Your explanation seems to make good sense for a moment, but then it occurs to me: In the case of the balanced lever on a pivot, gravity is working on its mass throughout its length and in equal proportion to the distribution of that mass, while in the case of the 'sideways' tonearm situation, the skating force (unlike gravity) is always being applied unequally only at the point which the stylus touches the spinning vinyl, no matter how the mass is distributed. Is this really analogous?

Shirasagi: You could make a more obvious demonstration by employing the smooth uncut track featured on some test records (older ones anyway) for adjusting anti-skate. The net effect of unequal side-weighting on skating - provided it is present - would be much more readily observable this way than by trying to eyeball the tough-to-see (and impossible to visually quantify with precision) stylus deflection differences.

Yes, I should not have actually said, "shifts the forces", I should say shifts the relationship of the forces. It gives the various different forces a different relationship (equation) as they relate to each other.
You are correct- if we hang a tonearm straight down, and get gravity to pull it to one side, and put it on the table again, there is no longer any gravity pulling it sideways. It would not have force to pull it to one side. In actuality, the force of the cartridge on the pivot point does not change either (unless we increase the tracking force).
If we visualize a tonearm hanging straight down with a radically offset mass, you can see that it would take a certain amount of pressure to hold it to hang straight down. And the offset weight is resisting gravity. Replace the gravity in this visualation with the pull of the cartridge. It takes more effort to pull the cartridge one way than the other.
While radically shifting the weight in this manner will not actually pull the cartridge in a direction, it will alter the resistance to such a pull. This then also changes the effect of the pull on other forces. The cartridge will pull to one side more than the other, not because there is more pull in one direction, but because there is more resistance in the other.
This can lead to some pretty deep thoughts on anti-skate. While it is the offset angle of the cartridge is what pulls the arm to one side, the pull is actually directly in line with the cantilever. But, we do see that the cantilever deflecting to one side (when we can see it). To use offset mass as opposed to actually applying an offset counterforce, might be a more effective, and accurate way to deal with anti-skate.

A quick note. I've used the offset HI-FI tweak for months now, since last fall, and have not the slightest doubt that it is effective. Regarding being able to see the cantilever I can't force anyone to agree with this, of course, but I've got a Denon DL-103D cart (with tag reading 1978) that has a fairly easy-to-see cantilever, and my table is placed just in front of a window which, with shade open, allows brilliant natural light to flood in. Anyone - I repeat, anyone - who doesn't have a fairly serious vision problem would be able to see the movement of this cantilever as it varies according to setup. Thanks, folks.

Thank you for sharing this, I tried it and am utterly delighted and awestruck! I had been quite happy with my fully Expressimo-modded RB250, but noticed that cymbals were not pronounced enough for my pleasure, I had been tweaking with mats and thought I had it solved, but then it backed up and I was at square one. I had acquired some of these bullet weights to see about spikes for my gear, they didn't work, but then brought them out for this suggestion and am very impressed!

Tw1,
for some reason or another I never discover this thread. Just to add something to the discussion I would like to mention the following: I opened a discussion at Vinyl Engine which concerns the theoretic background of effective weight in the lateral and vertical direction. Some links to texts written by the famous air arm inventor Poul Laadegaard heve been added. The thread is called:How important is arm resonance frequency? Can it improve sound quality? You can find it at page 4 of the Turntable Talk part of the forum overthere.

Perhaps you know of the existance of another theoretic paper on this subject? A site by Van Alstine on the web published a similar mod mounted on the cartridge, but I think that one is not good for tracking. the thread at Vinyl Engine leads us to a last open question: how does Mr Laadegaard himself think about the 1977 AES paper at the moment? Unfortunately he is very silent about this. He did not answer my email to the B&K- office in Denmark.
Jan

Hi Janvoorn, I have read much of the writings of Poul Laadegard, and even made a prototype of his famous linear tracking tonarm once. He is an interesting fellow. Thanks for the tip to the website.

The Van Alstine mod was completely different, because it was positioned at the headshell, and affected both the vertical and horizontal mass. But, it may have helped with azimuth control on unipivots.

Actually, this HiFi mod only makes up for the lack of engineering on the part of most tonearm designers. It seems that the majority of cartridges made are wanting a bit more lateral mass in the tonearm system.

Let me ask youguys a question. I've printed out the thread and I'm still reading thru it so I hope it's not been answered before.

I'm using a very crude version of this tweak on my backup 'table, a Sony with no antiskating (the arm is a POS). It seems to have cleared things up a bit.

My take on the tweak was a thin metal spatula (what I had at hand) for which I found what I thought was the mid-point, affixed with a couple tiny drops of glue to the top of the tonearm casing. I looked at it with a flashlight from all angles and it appears to be straight.

I later made 5-coin stacks, held together with drops of glue, and added one to each side of the rod, just for the heck of it. I can't say I'm noticing much further improvement.

Anyway, about antiskating. I noticed the rod isn't quite centered on the tonearm pillar (wonder just what I was doing when I marked the mid-point on it), but rather one of the sides is hanging out more than the other.

This end is on the 'outside'. Is this the 'right' side for the offset weight to counteract the skating force, or should I mount it the other wayround?

Thanks!

Hi Damian, while the unequal weights may possibly effect a change in anti-skating, it is not recommended to do that. It has other effects too, which might include affecting the azimuth, causing unequal bearing loading, among other things. If you need to adjust your anti-skate, I'd recommend approaching it from a direction that influences only anti-skate.

Dear friend: I have around 18 tonearms. You have a point that maybe it's valid, but when a tonearm manufacturer has a good design and a good execution ( it does not matter wich kind of tonearm bearing design ) you don't have to worried about it. If with this " mod " you have a different sound maybe is because your tonearm is not first rate.
By the way, you say that a heavy tonearm is a bad traking arm ( vertical ), well this is not in that way. All depends on the cartridge/tonearm match and in the tonearm bearing.
Cheers.
raul.

Rauliruegas, yes I agree that if the tonearm is properly designed, that there will be no need for my tonearm mod. Unfortunately, it seems that many are not properly designed. So, improving the lateral mass is appropriate in many cases, but not all. Also, it depends greatly upon whether the cartridge is low, medium, or high compliance, as to whether additional lateral mass is even needed. In any case, this mod is strictly for OL Silver and Rega tonearms, and it has been demonstrated that they perform better, with many cartridges, by having additional lateral mass placed in the proper location.

I have never presented this modification as a "panacea" for all arms and all cartridges, but strictly for Rega and OL Silver arms with lower and medium compliance cartridges. Other arms may also benefit, but that would have to be determined on a case-by-case basis.

Thanks for your comments.

Tom brings us back to the point about cartridge compliance and the efficacy of doing a mod like his. I have been thinking about this recently since I installed a van den Hul DDT-II Special in place of my previous Benz-Micro Glider M2.

The vdH's have higher compliances than is usual for most MC carts (and their upper-line models even more so than mine), yet the DDT does not seem to suffer from being run with the same viscous fluid damper settings I used with the Glider. But I'm not sure this would be the case if I had Tom's mod instead of the KAB damper, due to the point I made somewhere above about the added mass imparting not only increased resistance to lateral deflection of the tonearm (as does the viscous fluid), but also continuing intertia once put in motion (which damping fluid does not have).

This sheds some light on a problem that baffled me near the top, namely why Tom felt the mod increased susceptibility to skipping on scratches: it's the intertia - I just didn't put the two together before. There's probably a 'threshold' effect at work: light scratches may actually be less prone to cause skipping with the added weights installed, but these kind of scratches might not normally cause skipping anyway - while scratches beyond a certain magnitude (that acutally cause the stylus to break contact with the groove) may cause a lateral arm deflection that is less easily brought back under control once begun due to the added mass inertia.

Anyway, we see that increased lateral mass mandates matching to a relatively low-compliance cart, such as Tom's Shelter. This is of course no different a concept than the standard one about matching compliance to overall effective arm/cart mass, with the exception that Tom's use of increased *lateral* mass *only* means that there will be little or no effect on system resonance excitability due to infrasonic warps, footfalls and the like, or LF mechanical feedback (which tend to be primarily vertical in nature), nor due to the low bass content of lateral-cut (mono) or diagonal-cut (stereo) recorded music (since the added mass only lowers the resonance point, presumably already below the 20 Hz maximum). So bass performance is enhanced, tracking is maintained, and skipping susceptibility is worsened (but not if your records don't have scratches).

Still, you could say about viscous fluid damping that the bass performance should be likewise increased, tracking may even be slightly improved (fluid does provide a bit of extra vertical damping, though not as much as laterally, due intentionally to the shape of the paddle), and susceptibility to skipping is ameliorated (or at least reduced in magnitude when it occurs). At least one could think so. In my own listening tests with the fluid damper, I mostly heard a cleaning-up of the soundstage, a purer, more extended treble response, and bass that sounded more natural in timbre but not necessarily more extended or dynamic (those tests done with the Glider). I can state that the damper doesn't worsen skipping, but haven't done the tests to state that it really improves this aspect either. In any case, fluid damping does seem to permit the use of carts in any compliance range (indeed, the KAB product, dedicated as it is to the Technics SL-1200 table/arm, will likely be most often used with high-compliance MM carts featuring relatively high-mass tips and cantilevers, such as the models made for club DJ's and hiphop turntablists).

But since KAB evinces no interest in coming out with a fluid damper for Rega-sourced arms (despite my opinion on the market potential there), Tom's mod would seem to be it for owners of such arms - provided (as he states) that they are running a cartridge of suitable compliance. Looked at that way, what he essentially did was come up with a clever method to improve the match of his tonearm to his choice of cartridge, without paying a penalty in reduced trackability.

Thank you Alex, for your succinct description of the pros and cons of the mod, and the importance of matching the application.

I think it is worth pointing out that what a properly designed tonearm IS, is the result of continuing to try to improve the design, that is, further the knowledge and design of the technology. That is why it is so much fun that twl shares his improvements with us. Any tonearm can be improved. If it interest you, go back toward the beginning of this long thread and you will see what fun we all had in trying to determine the validity of Tom's modification. There is actually enough here to demonstrate that the modification is of proper design. This is a LONG and old thread. The mod (lateral mass) is proven in listening test, compatability, the theory behind the mod is also put to the test, and it is shown to be an improvement not only to the overall sound, but is a more properly designed arm with it.
If you are truly interested in what a properly designed tonarm is, and want to have real fun, notice how many highly regarded and well designed tonearms DO NOT take note of the the aspects of TWL's design, and if you execute it properly, many arms could be improved the same way. (notice that some arms have uprades that go in this direction). The rb-series of tonearms have some really good aspects to them, namely the design of the armtube and the bearings, as well as some aspects that are overlooked.
The mod works so well that the performance of the arm comes scary close to some VERY good arms, and evan surpasses a lot of very good arms in certain, important areas. It is amazing what you can achieve with a little knowledge of tonearm design.

I want to go just a bit further and break down just why I feel Tom's idea constitutes a intriguing and enlightening approach. In the past, before coming to some understanding (with the help of the contributors to this thread) of what the HiFi mod represents, I had - I'll assume like most of you - regarded effective mass as a monolithic quantity. Tom's insight made me aware that we should properly take into account two separate quantities of mass, vertical and lateral.

The reports above of those who've tried his mod testifies to the validity of his fundamental underlying proposition: that information retrival may benefit if these two quantities are not treated as being always interchangable - that in fact, performance may be improved if these two quantities are made slightly divergent. Two divergent effective masses instead of one also implies there being two divergent points of resonance (cartridge compliance still assumed to be constant in all directions). I wonder if this presumably 'double-humped' resonance distribution might itself be partly to credit for perceived performance gains, as a result of the altering of the system's "Q" characteristic to be less intensly concentrated at one specific frequency ; in other words, maybe simply making the lateral and vertical mass - and therefore resonance - components somewhat different from each other could be as significant a reason for improvement as the action of additional lateral mass itself.

This an untested hypothetical of course, but we do know that there is a several-Hertz range within which 'proper' system resonance may ideally fall, usually given as from 8 to 12 cycles per second. This value range is considered low enough not to be excited by music, but high enough not to be unduly excited by record warps, big dogs, passing 18-wheelers, distant earthquakes, etc. So there is obviously 'wiggle room' to for instance make the vertical-mass/cartridge-compliance resonance point = 10Hz while the (higher) horizontal-mass/(constant) cartridge-compliance resonance point may be brought closer to say 5Hz without having to worry about extraneous inputs of (primarily vertical) infrasonic energy ruining your tracking day.

The viscous fluid approach , while not imparting inertial effects (and in fact counteracting them), does little to damp such low frequencies, and won't really alter the distribution of the system resonance. (I want to stress here, in relation to this inertia business, that Tom's added weights do not encumber the cartridge suspension in a discriminatory manner that is out of the ordinary ; the suspension must deal with the tonearm's mass inertia anyway, whatever its value. Gravity helps maintain groove contact in the vertical dimension through the VTF setting ; laterally - particularly with really good bearings - it seems to me that inertial mass ought to be able to stand an increase at least roughly equivalent to the VTF.) I observed near the top that fluid damping ought to be superior to the HiFi implementation in terms of HF damping, and this analysis suggests that maybe the two concepts are actually complimentary.

Funnily enough, after so long since this thread began (and after having previously inspected my own tonearm to see if it could be made to accept something like Tom's mod, which I concluded it really couldn't due to its physical design), this late conversation spurred me to go downstairs and look once again - this time with a new notion in mind. And hot damn, there it was: the 1200 tonearm already incorporates added mass in the lateral plane! I'd been looking at it the whole time (the brain sure can work slowly... :-) I think a lot of gimbal tonearms have been made like this: it has a 'carriage' containing the vertical-plane bearings which itself rotates in the horizontal plane (it's mounted within the 'tower' assembly holding the horizontal-plane bearings, which is itself stationary). This 'carriage' structure is basically a rectangle, open in the middle (the arm passes through it), made of cast alloy about 1 1/2" wide by 3/4" tall by 1/4" thick, which incorporates the steel vertical bearings ; when the tonearm moves vertically it remains put, but it rotates in the horizontal plane right along with the tonearm when it is moved laterally. I would estimate its total mass as being roughly in the ballpark of Tom's fishing weights. D'oh!

Good points, Alex. In fact, some tonearms do have added mass in the horizontal plane, provided by the bearing housing structure. Others have a large bearing housing, but the bearings that control horizontal movement are only holding a low-mass ring which is part of the gimbal system, so those don't really help in that regard.

In early tests of the other OL arms like the Encounter and the Illustrious, I found that the horizontal mass(large bearing housing) in those arms was already sufficient to preclude the use of the HiFi mod. And in fact, they sounded better than my OL Silver with the HiFi mod. This shows that horizontal mass is important, but is only one aspect of the design, and other things still are very important.

Your comments about the amount of mass increase being similar to VTF force is very astute. However, the mass increase that I use is about 12g per side, or a total of 24g. This is placed at the pivot, which is not augmented by the F x D^2 multiplier of the long arm tube that multiplies the effect of stylus accelerations at the pivot. In order to counteract forces and accelerations that are multiplied by the leverage of the long armtube(9"), a larger mass is needed at the pivot, than the typical cantilever and suspension may be exerting at the headshell. Even this 24g increase seems insufficient. My testing has shown that even though the increased mass may seem insufficient to counter the forces and accellerations that the cartridge produces, it is the increase in Coulomb's Friction(static inertia) which is the key to this HiFi mod's performance. This increase in Coulomb's Friction causes the static moment of inertia of the tonearm system to be higher than the stylus deflections can overcome on a short rapid momentary acceleration during play. This is why the cartridge performance is increased, but the slower movements of spiral tracking of the groove are relatively unaffected. Higher amounts of mass increase could be counterproductive to normal arm movement across the record. I know we had this discussion about static moment of inertia earlier in this thread, but I neglected to mention Coulomb's Friction at that time. It is different than the typical dynamic friction that we are all familiar with.

Doug Deacon's HFNRR test record measurements with the Hifi mod installed on his OL Silver yielded a near perfect 11Hz vertical, and slightly higher horizontal with a Shelter 501 Mk II on his arm (if I remember his post correctly) Both were well below normal audio range, and above rumble frequencies.

Regarding your interest in higher frequency performance of the damping trough, it is interesting to note that studies have been done on arms with removeable headshells, and it was found that 1kHz was a typical resonance peak resulting from the joint of arm/headshell. If the damping trough works well at that frequency, it may well prove very effective on that resonance, as well as others.

A damping trough working in conjunction with increased horizontal mass is an intriguing idea which could merit some experimentation. I have not tried that combo personally. It sounds like a good idea.

Thanks for your input.

"Doug Deacon's HFNRR test record measurements with the Hifi mod installed on his OL Silver yielded a near perfect 11Hz vertical, and slightly higher horizontal with a Shelter 501 Mk II on his arm (if I remember his post correctly) Both were well below normal audio range, and above rumble frequencies."

From memory:
OL Silver
HIFI Mod
Tom's suspended counterweight (described above, I think)
Shelter 901
~ 9Hz horizontal
~ 11-12Hz vertical

The suspended C/W is not quite as heavy or as close to the pivot as Tom intended. OTOH, reducing the vertical moving mass would raise the vertical resonance frequency still higher, right?

If Alex's new thoughts are correct, then it's okay or even desirable to have the lateral resonance freq lower, and reducing it even more might have a good effect. I'll have to add some bubble gum to the weights, remeasure and do some listening. Any suggestions for the best flavor? ;-)

Doug

Doug, thanks for clearing that up. I couldn't remember exactly what you stated in your post, and I just made a mistake in writing that you had a 501.

BTW, I have always thought that Bazooka was the best bubble gum! :^)

Double Bubble. It reinforces the effect of the divergent resonance points... :-)

Tom, your technical analysis of what might constitute the optimum range of added lateral mass and why is a good deal more sophisticated than I could manage (not that I can't follow the gist of it, i.e., what matters are the forces in play at the stylus tip with mechanical multipliers taken into account, not the raw masses involved - I think). So I will just second it with an alternative observation: the existing counterweight on any conventional tonearm is at least as massive as your 24g of added weights, and I would guess probably more often 2 to 4 times that amount, whereas the cartridge, out at the end of the tonearm lever, is roughly 1/2 to 1/4 as massive (as the added weights). At set-up, the counterweight is first balanced against gravity with the cartridge installed, then moved inward toward the pivot to effect the desired vertical tracking force. This action could be seen as 'unbalancing' the cartridge in the lateral plane by the same amount as the applied VTF - and Tom's added weights could be seen as a method of 'restoring' static lateral balance by providing a 'counter-counterweight' that operates only in the lateral plane.

Of course that's not a literally true analogy, because gravity is operating only in the vertical plane, but the lateral accelerations applied by the spinning record at the stylus tip are real, and they can be presumed to be basically equivalent to the vertical accelerations (caused by same) that gravity is enlisted to help manage in the vertical plane. Now, because the groove wall is cut in a 45-degree "V" angle, the downward VTF applies the same restorative force in the lateral plane as in the vertical when the stylus is deflected side-to-side. There is a difference however: in practice, the cantilever is always deflected vertically upward by the VTF, even at rest, whereas laterally it always returns to center. Given that scenario, plus the fact that warps which need to be tracked by the tonearm are mostly a vertical phenomenon, there would seem to be elbow room so to speak for increasing what we might call the 'lateral dynamic tracking force' against which groove accelerations act in the lateral plane. In other words, we can think of Tom's approach (of increasing lateral mass) as effecting a sort of separate, and higher, "VTF" for the lateral plane.

These musings inspire a vision of what Basement refers to as a 'properly designed' (pivoted) tonearm: maybe such a creature would have not just a rear counterweight, adjustable forward and backward to effect proper tracking force, but also side counterweights concentric with the pivot point mounted on extensions of the fixed axle, adjustable in and out from the pivot in order to effect optimal lateral counteractance to forces applied at the stylus - while the whole shebang would be fluid-damped. (And: might such adjustable side-weights even be able to effect some form of dynamic anti-skating compensation?) This seems to me the logical extrapolation of Tom's mod...

Zaikesman,
I remember posting somewhere (maybe on this thread but who could find it) that side weights threaded for in/out adjustability would be useful. I think the tungsten side weights on the Graham 2.2 are like that (4yanx?).

My thought was just an instinct, not as well thought out as what you and Tom are doing. I really appreciate the continuing contributions to tonearm theory engendered by this thread. Maybe I'll uprade my HIFI Mod some day, though I can't imagine how I'd get the existing weights off without wrecking the arm.

To heck with this pivoting nonsense. I want a Kuzma Air Line! I'm off to buy a lotto ticket...

There are some really interesting thoughts here in the last few post, as far as thoughts or ideas that eventually turn into knowledge. It is for one useful when we attempt to measure and discover that the measurements are not exactly what we expect- we figure out there is something else going on and we learn something. One thing pointed out here is that the grooves of a record are cut at a 45 degree angle-so then how could a horizontal mass not have an effect on vertical mass? (as it relates to its affect on the suspension). I wonder how these grooves are cut into these various test records that are able to relate to being able to determine separete vertical and horizontal resonences, and wheather these are still existing the same way when the same system is playing a record with grooves cut at 45's. My ears suggest that as I listen to the differences with this particular mod is there is greater channel separation.
We all know that resonence points are important, and tonearm designers are sure to make sure they're designs fall within these parameters. There is also a definite importance on mass, and the placement of such, as it relates to the evacuation of energy, and it is clear in the more recent trends of the better tonearms that have recently added mass to they're arms in particular areas and gained improvements.
A little earlier on in this thread it was brought to our attention that the sidewieghts could be used to effect a change in anti-skate behavior. It made me think about the effects of bearing placement, as it relates to weight (or mass) placement, as it relates to the behavior and tracking ability of the arm. In both the immedia and the sme, the bearings are placed by the designers to minimize tracking error, according to the relative travel of the arm, BUT, changing the placement of the mass in a similar way, such as some of the aftermarket rega counterweights, and the upgrades on the graham, show similar results, without changing bearing placement.
The best unipivots in use today, namely the graham, the immedia, and the vpi, pay close attention to the placement of mass because they have to-it relates directly to the stability of the arm as it relates to tracking- and as designers shift and add mass, they continue to get better results. It is also, perhaps, that as the same attention is payed to pivoted arms, we get the same results, which might lead to the conclusion the while there are advantages to a unipivot as it relates to bearing quality/cost and friction, that perhaps it has more to do with the placement and attention of the mass.
Another case in point might be the popularity and performance of air bearing designs. Very complicated, and while they do show themselves capable of a high level of performance, it was a matter of time until pivoted, and unipovoted arms showed many of the positive aspects of the air bearing designs without the complications. Could very well be, that the sole advantage in actual use, of these air bearing designs is the vertical/horizontal mass relationships inherent in they're designs.
Of corse, the very best arms are very expensive, and rightly so because of the costly construction, as it seems that often certain improvements and uprades are costly to execute. There are some aspects of some costly arms where the quality of the construction relates directly to the performance. And then there are some aspects where improvements are made to the design that are by chance, or because the designer thinks the improvments are the result of what the intention is. That is why this thread is so fun. That is where this thread is at, and that is also why it is so amazing that as TWL comes up with these ideas and experiments that seem to break the rules, it not only forces us to change our perception of what a "properly" designed tonearm is, we make great sounding improvements that I am convinced would further the technology the more we understand them.

Doug, I thought about making the weights threaded for adjustability, but finally decided that it left too much to chance. Also, any threaded pieces will set up resonance points at the joints, unless very securely locked, and even then they could still have some(ie. removeable headshell joint). They are right on the axle, so resonance could be a problem. Also, that would raise the cost noticeably. It would be worth a try for an experienced user who knows what he's doing with cartridge compliance matching.

I'd be willing to make some units with adjustability for someone, but the machining costs and labor might make them quite expensive on a small scale manufacturing basis. I've talked with the guys at Starsound about making this item in a more professional(and possibly adjustable)form, but so far it is on the back burner.

This plain model that I'm making has a pretty good working range for most cartridges(5cu-15cu), and is simple and cheap.

Alex, as you mention, the actual lateral mass is the combined mass of the tonearm, cartridge, counterweight, bearing housing, AND my added weights. All arms, of course, have some amount of lateral mass built-in as part of the basic components. Usually it is similar to the vertical mass. But some tonearms have designed-in some additional lateral mass to give similar benefits as the HiFi mod has, notably the OL Encounter and Illustrious which do not need my mods.

Regarding your multiple resonance point theories, I think it has merit. By distributing the 2 resonance points over a wider range, it will have less additive effects resulting in lower amplitudes, but over a wider range. By keeping this range small and in the "ideal" range between 8Hz and 12Hz, the additive amplitudes can be minimized and still not have adverse audible effects. In Doug's case(Shelter cartridges) the 11Hz vertical and 9Hz horizontal both fall in the "ideal" range, and are wide enough apart to reduce additive amplitudes. This will result in significantly less mass/resonance amplitudes compared to having both(vert.& horiz.) resonating at the same freq. and causing a doubling of the resonating amplitude. In an ideal world, we could try to produce these amplitudes at the exact same point, but 180 degrees out-of-phase, thus causing cancellation of the resonance altogether. I haven't figured out how to do that yet. So this narrowly distributed resonance may be the best way to go so far.

As far as the idea you had about the counterweight with side-weights, the weights must be located exactly at the pivot axle, or else you are adding mass to the vertical component. My weights are small-diameter, and concentric with the center of the rotating bearing axle, so they have minimal(if any) effect on vertical mass. All of the HiFi mod effect is on the horizontal mass, so as to keep vertical mass unchanged, for good warp tracking. In addition, having the weights made of lead will damp any resonances that might adversely affect the performance, and the extra weight attached to the axle actually makes the axle itself less likely to become excited or chatter in the bearing clearances.

In some cases, a very simple idea or device can address a wide range of problems effectively, as long as it is well thought-out. I have resisted doing any big changes to it, since it is working so well as it is.

I think this thread is turning out to be a lot of fun.

Basement, I agree that placement of mass, as well as the amount of mass in various planes, is very important to the overall success of a tonearm design. This is still an evolving art/science, even after all these years. A natural inquisitive nature is needed to spend time thinking and testing new ideas. Maybe some people will be spurred into making the next leap forward to a totally new tonearm design, or just the next evolutionary discovery, after reading some of our posts here. In any case, I think this thread has become one of the real reasons why forums can be so good for the development of the hobby.

I really appreciate all of the posts and ideas that have been presented here on this thread, in a most genuine way. Maybe all of us "tonearm geeks" needed someplace to converse. I'm glad it is working out the way it is.

Tom, just to clarify, what I wrote was intended to describe a tonearm having *not only* a conventional counterweight, but *also* side-weights mounted as you specify (I included the detail about bearing-axle concentricity, for instance) - *not* a counterweight with side-weights added to *it*, as it seems you may have aprehended.

Doug, thanks for making clear that you posted earlier about the idea (which I'm sure Tom must have also had from near the beginning) of making the side-weights adjustable. I've thought about this a little more, and come to the conclusion that a production tonearm with this feature would probably need both a provision for threaded-post fine adjustability, plus a small assortment - maybe three different mass values - of exchangable side-weights, to yield a practical working range of variability that's broadly compatible with cartridges of differing compliance. As far as the potential sore point of resonance at the threaded (or whatever) junction goes, I don't think this looks too bad: you already have an adjustable counterweight that's affixed to the tonearm proper, so doing something similar that's on the bearing axle - rather than directly in the tonearm 'mechanical path', such as a detachable headshell - doesn't seem overly daunting to me.

Alex,
You're right with all those ideas I think. That would make an arm very broadly compatible, especially if a couple different counterweights were also included. Then one could really tune in both vertical and lateral moving mass. Whether resonances at the threads would be a problem I don't know, but quality machining and very fine theads would help, and they'd give finer adjustability too. Maybe a Delrin female thread insert to prevent metal-to-metal contact?

Another idea I'd like to see is a VTF fine-tuning adjustment screw that threads into the back of a locked down counterweight. You could quickly add or subract a few 100ths of a gram by moving the screw in or out without having to move the C/W and remeasure. Big benefit for VTF-sensitive cartridges like Shelters. We change VTF every time the weather shifts: 1.95g in January, 1.70g now, who knows in July. The screw would be quite tiny, we do small VTF adjustments on our modded Silver with a rotating paper clip mounted on the HIFI weights.

Of course I'm never retreating from my main position: Kuzma Air Line or bust!

Speaking of what goes on behind the counterweight, that's where I would work on putting the fluid damping trough, to get the paddle farther from the pivot point than is normally possible on the platter side of things. (The Townsend trough-at-the-headshell-over-top-of-the-spinning-record design notwithstanding, which makes me nervous and seems like it would be a bit of a pain in the butt when it comes to actually playing a bunch of records, although I'm sure that it is the most effective implementation possible from a damping standpoint). So instead of having a relatively massive counterweight very close to the pivot, I'm imagining an extension of the tonearm continuing to the rear, terminating in the damping paddle, with only a relatively light counterweight needed.

I just had an intriguing thought: mightn't Tom's idea be somehow translatable to and beneficial with the Well Tempered tonearm suspension design?

Twl:
I've just looked over my OL RB 250 tonearm and I don't see where one would "press fit" the weights. There aren't any real "nuts" to press them onto. Did you remove something else on the tonearm?

Hi,
The standard RB250 has end caps which are pressed into the bearing yoke on both sides. Sometimes these are already removed. If they are still there on your arm, and you don't want to mess around with taking them out, then just apply these same principles to your application by grinding a depression in each fishing weight that approximates the curve of the brass end caps. Then glue or Blu-tac the weights right to the brass end caps, and you are ready.

Be careful to choose a fishing weight which is shaped such that it will not interfere with your cueing lever.

I believe!!!

For less than $5, I purchased 2 fishing weights from the Bass Pro Shop and some Blu-tac equivalent from the Home Depot. It took 3 attempts to figure out how much blu-tac equivalent (actually, mine is yellow) to use, but I no longer feel the need to pull out the super glue. The weights haven't slipped for a week now.

I have noticed that my OL Silver / Shelter 501 is now even more sensitive to VTF (1.85 grams by my Shure seems to work best for me).

If you have an arm / cartridge that could benefit from this tweak, you are a fool if you do not try it. For less than $5, this non-permanent mod is a must.

I agree, I did it and was amazed.

I found this thread from a post today on the AA Vinyl Asylum.

Anyway, I came, I read, I tried the mod. I have an RB250 with the OL stub/counterweight, OL rewire, etc. I just superglued the 7/16OZ bullet weights to the bearing caps and got on with it. The results...

Wider and more 3D soundstage, initial bass impact is much snappier (but not deeper). Its like everything became more focused. The highs got a lot better - I had no idea how mushy my setup was before. Good stuff.

But the best improvement is that well-recorded pianos now have that chesty piano sound, instead of a throaty piano imitation. Real, full, reverberant piano. Shweet.

Thanks TWL and all for the best $.79 I've ever spent in audio.

Pete Fowler, Austin TX

Tried this with my Rega P25/RB600/cart setup and it works great. Used the yellow "blu-tack" mentioned within the thread, and steel bullets (can't find any lead ones in NH, but if someone whats to ship me a pair, feel free to send some up here!). I also have a Denon DL-103R on order, and am interested to see how the tweak works when the Denon's installed. I know the DL-103R isn't supposed to be the perfect match for the P25/RB 600, but thread comments have convinced me using this tweak with the Rega will prove otherwise.

What a great low-cost removable upgrade - thanks!

To all, and TWL especially - changed over my cart to a Denon DL-103R, with the bullet tweak previously installed. After setting up and burning in the cartridge (TWL - no VTA adjustment needed on the Rega!), I can easily attest the DL-103R with the tweak is a wonderful match. This cart nearly nailed the HFNR Test record's torture track, and IMHO that is saying something. What a pleasure to listen to, and I'm happy to have the $$$$ in my pocket that I could have spent on much more pricey carts. TWL, thanks again for the recipe and advice, esp. on the DL-103R.

Very glad you all are enjoying the mod.
Thank you for your kind comments.
My satisfaction comes from knowing people are getting better sound by using my invention.

Still a 100% success rate, no dissatisfaction ever reported.

This may be the only audio item that everybody likes.
It seems that the major considerations for universal appeal are:
Great sonic results,
Very low price.

BTW, I just read on the OL website about their new "Conquerer" tonearm(new "flagship model", over $4k). It seems one of the major upgrades has been to increase the lateral(horizontal) effective mass even further.
Where have we heard that before?
It feels very good to have been on the vanguard of a trend in tonearm improvement.

"H.I.F.I" = Horizontal Inertia Force Increase

Note: Remember this mod is designed for cartridges with compliance ratings of 15cu or below. No Grado or other high compliance cartridges should be used with this mod, as it does not help with a "whippy compliance" cartridge, and may cause Grado cartridges to do the "Grado wobble" because of mismatch. It gives the most satisfying results with low compliance cartridges like Denon DL103 and 103R, Shelter, Koetsu, and the like, with below 10cu compliance rating. Cartridges with 10-15cu compliance rating will get a good improvement too, but not quite as astounding as the lowest compliance ones. The lower compliance the cartridge is, the more likely it is to "overdrive" the horizontal effective mass of the tonearm, which is why the HIFI mod works so well with lower compliance. A higher compliance cartridge may likely already be horizontally stabilized by the standard effective mass of the arm, and needs no change in that parameter.

Hi Tom,
A few months back someone on VA tried to compare a 103R and a Shure V15xMR on a HIFI-modded RB250. Not surprisingly, the Shure came a poor second. I told him he'd have to remove the Mod or remove the Shure. ;-)

He apparently was under the impression his modded arm would improve the performance of any cartridge. Strange that anyone could think so after reading your first post on this thread but apparently he had missed the point, so I guess it can't hurt to reiterate.

Cheers, good to see you posting again!

Yes Doug, as you know, the HiFi mod is related to matching the cartridge to the effective horizontal mass of the arm, and can therefore be mismatched, if the cartridge has too high compliance for this mod.

It is not "universal" in application.

Thanks for your observations and comments.

Doug: Sorry to go off-topic for a sec, but I noticed at soundfountain.com Audio & Music Bulletin that you were using the RSR outer record ring. Did you make yours, or buy it complete? If it was the latter, what do you think of the pricing for the quality? From the text it seems implied that one could be fabricated for my SL-1200, though I don't know if it would fit in between the platter and my KAB damping trough...

Doug,

I know you posted about the ring, but damned if I could find it. I'd like to know what it cost too.

Joe

Over the last year as time/$ have permitted I worked on trying to get my system to sound like what I thought it should sound like. I played a horn growing up and used to go see the Minneapolis Symphony perform with my family along with many rock/jazz concerts. My goal was to try and duplicate what I felt an instrument sounded like when played. Sometimes because of the venue you had really good acoustics but even in a good hall there are better seats than others. I was trying to get a sound that I felt would be in the middle maybe 20 rows back. Depending on the venue and what type of music or concert it is, especially in my high school days at a rock concert in a hockey arena, then the ambiance and acoustics didn’t matter because you were so high.

Ahem, anyway, jazz, blue grass or acoustic concerts of late have been seen at The Egg in Albany, NY, which is an outstanding venue and has extremely good acoustics. After doing a lot of reading on acoustics and listening to my digital front end I decided I had to fix the room before it could ever be close to something I would enjoy. I thought about building different designs and could have since I’m fairly handy but in the end I bought manufactured bass traps called Realtraps. Spent $1300 and bought 6 bass traps and 2 high-frequency traps. The traps are sized 2’x4’ and 2” thick. I have the HF traps located approximately at the side mirror points. 4 bass traps up on the front wall and 2 bass traps on the rear wall. This made a major difference in sound quality, smoothing and dampening all frequencies without taking to much out of the room and over-dampening it. I could now turn up the gain on the pre-amp without over-whelming the room and rattling the windows and floor joists. I would like to measure the frequency response of the room but haven’t done that since I don’t have the tools yet. I’d bet there are still improvements to be had here.

I finally finished building and finishing the maple table to sit my VPI-TNT 3.5 turntable on. I anguished over where to put the table because I didn’t want to screw up the sound stage that the Gallo speakers portrayed on the front wall. In the end, I really didn’t have any good choices and with restrictions on phono cable leads to the pre-amp and room considerations I had to set the table up right in the middle of the front wall. So far, this seems to be ok and I haven’t noticed any detrimental sound stage effects.

Spent the last couple of weeks twiddling with the TNT and all the different adjustments you have to go thru to get it right. I had bought a Wally protractor to adjust the Benz Micro Lo.4 moving coil cartridge mounted to an Incognito rewired, VTA adjustable Rega RB300. I also installed the Expressimo heavy weight. I had done all of the adjustments and it sounded pretty good but the instruments semed “thin” or “light”. There was bass but not with authority. There were drums but no “snap” to them. So I bought some 10K pots and made up adjustable cartridge loading resistors and installed them in the CAT pre-amp. After experimenting with these for several days it seemed around 300 ohms gave good results so I made up fixed 324-ohm load plugs and installed them. This made a fairly large difference and things sounded much better but it still didn’t sound really great. Not bad, just not what I felt it should given the quality of components. Still sounded “thin” and “light” compared to what I felt was a more dynamic sounding CD player. This annoyed me big time! I had bought TWL’s Hi-Fi mod last fall but because my TNT was down while I built the maple table I had never installed them. I hand reamed the 12-gram lead bullets out to 21/64’s which made the side walls really thin but they now fit over the bearing cap nuts. Super glued them in place and let dry for a day. Went thru all adjustments again being particularly anal.

This next part is going to sound so much like “me too!” What can I say? Now, dynamics kick ass! Full, solid, correct sounding. Bass lines and drums sound just like you think they sounded when recorded. A full dynamic sound but not so much that you feel it’s wrong.

I’ll give a couple of examples. I have the Classic Records release, 200 gram, Cat Stevens, Tea for the Tillerman, side 1, Hard Headed Woman, huge difference in bass, acoustic guitar, voice. Very solid dynamic sound. The authority just sounds right. Even my tin-eared wife noticed it easily.

Next: Pink Floyd, Mobil Fidelity, DSOTM, side 1, Money, Us & Them - I wanted to break out my rolling papers on this change. Really fabulous!! Bass, guitar, voice, all so much more real and dynamic sounding.

Next: Steely Dan, MCA, Gaucho, side 1, Babylon Sisters, Hey Nineteen – This was fantastic! Drums sounded like they were in the room, voice, horns, guitar, just great.

Finally: The Dave Brubeck Quartet, Classic Records release, 200 gram, Time Out, side 1 – all of it. For my ears this is my test record. Fantastic sax, outstanding drum work and some fine bass lines. I actually feel Dave’s piano is the weak link on this record. Anyway, maybe 10x better. Not really sure how to quantify how much better but it goes from sounding pretty good prior to Hi-Fi mod to just plain F****** great!

Call it $1 buck for lead weight and $1 for super glue and I get this kind of improvement? I know the Incognito rewire and Expressimo heavy weight didn’t make this much difference and they cost several hundred. Yes, I think they made a difference but not to the degree these stupid lead weights made.

Maybe my best analogy would be when I installed a stage 3 hot chip in the computer of my turbo Audi S4. It went from sort of quick to bat out of hell get to know your local state trooper fast. It really made a quantum difference and that’s what these lead weights did. If Tom charged several hundred for it you would still after hearing the change think it was worth it. Thanks Tom! Now, where are those damn papers…

For pics of my system see:

http://forum.audiogon.com/cgi-bin/fr.pl?vevol&1054441548&read&3&4&

Hi guys, and sorry to Twl for the OT. I bought my RSR fully assembled from SoundFountain. I believe Rudolph's taking pre-orders for another batch.

My only niggle is that the edge was a bit rough. This doesn't affect functionality, it just doesn't look as pretty as it might. Rudolph has switched suppliers in an effort to improve this.

Joe,
My short user review is posted on the site linked by Zaikesman, scroll down to near the bottom. Short version: several worthwhile sonic positives, no sonic negatives.

I'll start a new thread (probably tomorrow) so as not to continue this hijack. I have information that will be of value to Zaikesman and perhaps of interest to others as well.

Mr. Slate, glad to have been of service to you.

Just a simple use of basic materials, properly applied.

Anothet off topic post, but Tom, you are being awfully quiet on the Teres/Quattro thread.

First you disappear, then you leave the Teres torch to Doug, Lary, and myself.

SHAME ON YOU!!

Good to see ou back.

"Just a simple use of basic materials, properly applied."

Twl comes out of hiding, and then tries to hide behind himself with a masterpiece of understatement. Nice try Tom but I'm not buying it!

In addition to a HIFI-modded OL Silver, I've heard my Shelter 901 on the following arms:
- Basis Vector ($2,895)
- Graham 2.2/IC-70 ($3,900)
- TriPlanar VII ($3,900)
- Schroeder Reference ($6,500)

These arms outplay the $900 Silver in virtually every respect, as they should. But a HIFI-modded Silver tops them all in one parameter: the speed and extent of leading edge transients. None of these kilo-buck arms holds the cartridge as steady for the initiation of a big groove modulation. Referring back to some of the early discussions above, even the unflappable TriPlanar's adjustable damping does not stabilize the arm as well as the HIFI mod for attack rise times and amplitudes.

A HIFI-modded OL or Rega may be the best arm in the world for leading edge dynamics. Just a simple use of basic materials, properly applied. :-)

Thank you, Doug.

As you know, I am very sensitive to dynamics in general, since it is my belief that dynamics is where much of the emotion in the music lies. As music is an emotional expression, it is very important to me, to have this emotion properly conveyed. The power of macro-dynamics, and the subtle nuances of micro-dynamics, and their attendant emotional contexts really bring the intent of the composer and musicians to the forefront, and I need to have that in my musical presentation, as effectively as possible.

This is why I strove to find an improvement in that area for the tonearms. I just wanted to get that information off the record, and into my system.

It is also why I use very high efficiency speakers, which have an extremely low dynamic threshold. These speakers with 100db efficiency move at the slightest electrical impulse, and therefore have extremely good microdynamic performance. It would take a much higher level electrical signal to even get an 80db efficient speaker starting to move. This low-level signal resolution of high efficiency speakers is another key to hearing all the music available on the disc. I effectively reach down 10-20db deeper into the dynamic range of a recording with a system like this. Low level detail really comes out. My speakers are producing details which don't even get a "normal" speaker into motion.

Also, low power SET amps are very delicate in their presentation of the low-level details and can only power high-efficiency speakers like I use. The combination of these items together really makes a very enjoyable listening experience. Of course, I went with an incredible combination of OTL-SET and single driver loudspeakers, which do away with crossover distortion, and effectively drive the speaker cones directly from the output tubes, which doesn't hurt any.

A system is just that: a system. If you know what you want, and know how to get it, you can assemble a very enjoyable package of products which will really rock your boat. It doesn't have to be the most expensive, it just has to be what you like.

Ah, the magic of low level detail and micro-dynamic nuance. Yum. These allow the real humanity in the music to come through.

I "knew" this intellectually but had never really heard it until we got a new cartridge. Comparing the ZYX Airy to the Shelter 901 is perhaps something like comparing your amp/speakers to mine. There's little or no loss of macro-dynamics, but the Airy's ability to play down to very soft levels with subtlety and nuance really breathes life into the musicians. It's at least the equal of a Koetsu RSP in this regard, probably better, but without the syrupy warmth.

From what little I've found to read about them, all the ZYX models seem to share this trait, to varying degrees I suppose. I don't recall if you've heard one but I urge you to try. (That 501 can't last forever!)

Of course I should follow my own advice and consider changing directions with our speakers and amplifier. We're not quite ready to give up "full" frequency response though, particularly since we enjoy stuff like organ music with its low pedal notes. If you'll forgive the obscenities, would either a sub or active X-overs work in a setup like yours?

Joe, I haven't been doing much posting here lately, because frankly I've been a little tired of some of the argumentative posters. It made being here much less fun than it used to be.

Doug, I really like the ZYX Airy. It is a great cartridge all-around. I have been recommending the ZYX cartridges for quite awhile. I'm sure you've seen my posting about them.
Right now my finances don't allow me the luxury of moving in that direction. I'm pretty much stuck where I am until things pick up financially for me.

Mr slate I'll be right over with those papers! Anyway, I still want to do the mod, but now need a good MC to use. I have started a new business with my wife, and plan on rollin' in the dough in a few weeks. Well at least as much as selling cookies to teenagers will allow. I believe I will go with a Denon 103r, just need to decide who to go through. Any suggestions? Then I will be ready to mod out my 250 to the final tilt. I believe I will leave the re-wire last, after reading Mr slate's post.

Colitas,

Get the 103r through Audiocubes 2. Look here:

Audio Cubes II

The price went up to $249 + shipping, but I think that's the best deal you'll find. I got mine from them, and it arrived in about 5 days. Not bad from Japan.

If you have not figured it out from this thread, Tom's tweak is a must do. Probably the most dramatic improvement you will ever make, especially for the money.

Tom,

I know what you mean. It has taken a lot of effort not to post on the Beta testers thread until I actually finish my tests. A prime example of how far off topic and ridiculous some posts can get. While I like to get sarcastic once in a while, as Paul did in his excellent "ninja" reply, the temptation to to actually call someone an asshole instead of just alluding to it as I did, is almost overwhelming.

Joe - Thanks for the 103R link. I ordered one of these today.